Spark intensifier gap with a transformer coil around the cable



April 29, 1969 R. R. I Ewls SPARK INTENSIFIER GAP WITH A TRANSFORMERCOIL AROUND THE CABLE Filed Feb. 9, 19e? INVENTQR RALPH R. LEWISv 'Mahervf zum Y ATTORNEYS United ,States Patent O 3,441 797 SPARK INTENSIFIERGAPWITH A TRANSFORMER COIL AROUND THE CABLE Ralph R. Lewis, 3 WhitneySt., Saugus, Mass. 01906 Filed Feb. 9, 1967, Ser. No. 614,858 Int. Cl.H011 29/96 U.S. Cl. 315-57 1 Claim ABSTRACT F THE DISCLOSURE A sparkintensifier adapted to be connected between the high voltage terminal ofthe ignition coil and the central terminal of a distributor head of aninternal combustion engine comprising an auxiliary gap defined by afirst electrode having a threaded shank connected through a wire to thehigh voltage terminal of the ignition coil and a second electrode spacedabout 0.095 inch opposite said first electrode having a threaded shankconnected through a Wire to the central terminal of the distributorhead, a cylindrical ring-shaped supporting member of acid-resistant,corona-resistant insulating material with diametrically oppositethreaded holes into which the threaded Shanks are screwed, enlargedheads having smooth, parallel faces preferably slightly concave, on saidelectrodes defining the adjacent ends of said electrodes, a coil ofinsulated copper wire having about 40 turns surrounding the threadedshank of the first electrode, preferably wound tightly `and smoothlyover the lead wire resulting in a cone-shaped coil close to ring-shapedsupporting member, a cylindrical housing of acid-resistant,corona-resistant insulating material having a partition near the middlethereof adapted to support and center the second electrode, centrallyapertured and walls on each end of the housing in alignment with theaxis of the auxiliary gap adapted to maintain the auxiliary gap coaxialwith the housing and perforations in the partition and in the end wallnearest the distributor, adapted to permit free circulation and changeof air.

Background of the invention The field of. the invention iselectric lampand discharge devices, and the invention is particularly concerned withseries gaps and an intensifier in the lead-in.

Spark gap intensifiers for automobiles and other internal combustionengines are known in the prior art, such as those disclosed in U.S.Patents 2,684,451 of Castangay and 2,454,714 of Osterman. The utility ofthe series gap in an ignition system was confirmed by the U.S. Bureau ofStandards, NACA Report No. 57, page 176, of 1919.

Some of the limitations of the prior art devices are the necessity ofhaving a separate series gap for each spark plug, the individualadjustments necessary to start and maintain the current fiow, thematerials of construction which were poorly suited for use in theenvironment of a high intensity, high voltage pulse spark gap and thevariable operating characteristics under different atmosphericconditions.

Summary of the invention It is an object of the present invention toprovide an improved ignition system spark intensifier.

Another object of the invention is a spark intensifier for location inseries with the coil and distributor of -an ignition system.

A particular object of the present invention is an ignition system sparkintensifier having a spark gap set at a predetermined spacing.

Still another particular object of the invention is a spark intensifierhaving `a coil of wire surrounding the spark gap electrode on theignition coil side to provide improved engine starting.

3,441,797 Patented Apr. 29, 1969 ICC Upon further study of thespecification and claims other objects and advantages of the presentinvention will become apparent.

According to the present invention, an ignition system spark intensifieris provided which comprises an auxiliary spark gap interposed 'betweenthe high voltage terminal of n ignition coil and the central terminal ofthe distributor ead.

The improved spark intensifier comprises, preferably, two austeniticsteel screws, resistant to acids, acid fumes, ozone, and corona,threaded through the inside diameter of an acid-resisting,corona-resisting, insulating ring in a head-to-head spaced relationship.A coil of insulated wire is wrapped around the lead wire extending tothe ignition coil and the insulating ring is supported by anacid-resistant, corona-resistant, petroleum products-resistant housinghaving perforations for free circulation of outflow gases.

Photo-recordings of the oscilloscope displays of the high tensionimpulses of the present invention and the prior art devices were madefrom ten millisecond sweeps. The recordings indicated that the impulsesof the invention followed a single ionization path with the result thatmore heat is dissipated into the gasoline mixture with less heat intothe metal of the spark plug walls or electrodes. This heat dissipationproduces longer spark plug life and fire power. The shorter durationsingle spark of the present invention requires less energy to fire thespark plugs and less heat is generated in the secondary system with aresulting longer life for the components. The spark pattern of thepresent intensifier is reproduced consistently and otherwise fouledspark plugs continue to operate. Because of the present device, abovenormal primary ampera-ge which leads to burnt distributor points due tofouled or shorted plugs are eliminated.

Brief description 0f the drawing Description ofthe preferred embodimentsThe improved spark intensifier is connected between the high voltageterminal of the ignition coil 1 and the central terminal of thedistributor head 2. Instead of the usual continuous cable connectingthese two parts, there is interposed an auxiliary gap 3 comprising twoadjustable electrodes 4 kept in spaced relationship to each other `bycylindrical ring 5 of acid-resistant, corona-resistant insulatingmaterial. The cylindrical ring has two diametrically opposed holes 6screw threaded to receive the threaded shanks of the electrodes 4. Theremote ends of the electrodes are pointed to facilitate their endwiseinsertion into the free ends of high voltage cables 7 and 8. The freeends of the electrodes are much wider than their Shanks and are smooth,parallel and preferably slightly `concave on their adjacent faces.

The gap 3 may be varied between 0.060 and 0.120 inch and the preferredspacing is 0.095 inch. A suitable material of construction for thecylindrical ring 5 is compressed fiber or corona-resistant, non-porous,waterproof, acid-proof, ceramic or plastic material.

The auxiliary gap 3 is given additional protection and support by acylindrical housing9 of insulating material through end walls 10 and 11of which the cables 7 and 8 are passed. The insulating acid-resisting,corona-resisting material of the housing 9 is suitably an unplasticizedpolymer such as polypropylene or linear polyethylene.

In the middle of the housing 9 there is a partition 12 having a centralaperture to receive an acid, corona, and petroleum products-resistantboot 13 on the cable 8, and additional apertures 14 for free circulationand change of air. The end wall 11 has perforations 15 to provide freecommunication with the outside air.

A noise and static suppressor 19 suitably surrounds the housing. Thesuppressor is a tube of thin metal, preferably stainless steel isolatedwith Mylar lilm.

The cable 7 which is connected to the ignition coil 1 carries at itsouter end immediately adjacent the ring S a coil 16 of enameled copperwire, with the two ends connected to each other, as shown in FIGURE 2.The wire of coil 16 is suitably #28 wire and has a multiplicity of turnswith 40 turns preferred. The coil 16 is preferably provided with awrapping 17 of a suitable tape, such as Mylar, which is non-stretchable,inert, nonporous, high dielectric, and a boot 18 is fitted over theoutside thereof. Boot is resistant to acids, corona, petroleum products.

This improved auxiliary gap prevents or diminishes spark plug currentleakage. The high tension current from the ignition coil to the sparkplug (through the rotor of the distributor) surges from zero to peakvoltage (or to spark-over voltage if lower) and back again to zero everytime the distributor points open to produce this high voltage. This,however, does not occur instantaneously. The normal rate of voltage riseto tire the plug is about 1%20000 of a second, and the current leakagerate across the spark plug coating to the ground is about the same. Thevoltage rise in this auxiliary gap is, however, faster and higher andtherefore the voltage delivered to the spark plug is initially highenough to generally tire the plug. The voltage rise time at the plug isabout a millionth of a second and the plug therefore iires before anyappreciable leakage can weaken the spark. The auxiliary gap also permitsuse of plugs with wider gaps and longer use thereof without regapping.Wider gapped plugs are known to improve lower speed operation, and withthis auxiliary gap there is ample voltage to fire the plugs at allspeeds with wider gaps.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claim.

Having thus described my invention, I claim:

1. A spark intensifier adapted to be connected between the high voltageterminal of an ignition coil and the central terminal of a distributorhead of an internal combustion engine, said intensifier comprising:

(a) a first electrode having a threaded shank connected to said highvoltage terminal and a second electrode having a threaded shankconnected to said central terminal, said electrodes having heads withparallel faces to form an auxiliary gap in series with the main sparkplug gap;

(b) a cylindrical ring-shaped electrically insulating supporting memberpositioned transversely of the auxiliary ga-p andi having diametricallyopposite threaded holes into which the threaded shanks of the electrodesare screwed;

(c) a two-chamber housing of insulating corona and acid resistingmaterial comprising a cylindrical body with centrally apertured endwalls and a centrally apertured partition near the middle of the body,the electrodes and their ring-shaped supporting member being supportedsolely by the end walls and the partition, with the ring-shaped memberon that side of the partition which is facing toward the ignition coil,the partition and the end wall that is nearest the distributor headbeing provided with perforations to permit circulation of air; and

(d) a coil of insulated wire in the housing and surrounding the threadedshank of the lirst electrode.

References Cited UNITED STATES PATENTS 1,326,036 12/1919 Dunbar 313-1471,508,622 9/1924 Smith 315-62 1,968,225 7/1934 Shell et al. 315-622,896,120 7/1959` Spittler 315-58 X 3,267,325 8/1966 Why 315-58 X3,191,133 6/1965 Texsier a 315-58 X JAMES W. LAWRENCE, Primary Examiner.

C. R. CAMPBELL, Assistant Examiner.

U.S. Cl. X.R.

